import path from "path";
import { SKIP } from "unist-util-visit";
import { processMatches } from "./unified-processors";
import type { Plugin, Compiler } from "unified";
import { Element, Text, type Root } from "hast";

const EMOJI_REGEX = /:[a-zA-Z\d-_]+:/gims;

export type CustomEmoji = {
  id: string;
  name: string;
  keywords: string[];
  skins: { src: string }[];
  native?: undefined;
  // added by the library; we don't need to set it
  shortcodes?: string;
};
type CustomEmojiCategory = {
  id: string;
  name: string;
  emojis: CustomEmoji[];
};
export type CustomEmojiSet = CustomEmojiCategory[];

type NativeEmoji = {
  id: string;
  keywords: string[];
  name: string;
  native: string;
  shortcodes: string;
  unified: string;
};

export type Emoji = NativeEmoji | CustomEmoji;

export const customEmoji: CustomEmoji[] = [];

export const cohostPlusCustomEmoji: CustomEmoji[] = [];

export const indexableCustomEmoji = new Map<string, CustomEmoji>(
  customEmoji.reduce<[string, CustomEmoji][]>((collector, emoji) => {
    return [...collector, [emoji.name, emoji]];
  }, [])
);

export const indexableCohostPlusCustomEmoji = new Map<string, CustomEmoji>(
  cohostPlusCustomEmoji.reduce<[string, CustomEmoji][]>((collector, emoji) => {
    return [...collector, [emoji.name, emoji]];
  }, [])
);

type ParseOptions = {
  cohostPlus: boolean;
};

export const parseEmoji = (options: ParseOptions) => {
  const compiler: Compiler<Root> = processMatches(
    EMOJI_REGEX,
    (matches, splits, node, index, parent) => {
      const els = splits.reduce<Array<Element | Text>>(
        (collector, curr, index) => {
          const currNode: Text = {
            type: "text",
            value: curr,
          };

          const pending = [...collector, currNode];

          if (index < matches.length) {
            const emojiName = matches[index].slice(
              1,
              matches[index].length - 1
            );
            let emoji = indexableCustomEmoji.get(emojiName);
            if (!emoji && options.cohostPlus) {
              emoji = indexableCohostPlusCustomEmoji.get(emojiName);
            }

            if (emoji) {
              pending.push({
                type: "element",
                tagName: "CustomEmoji",
                properties: {
                  name: emoji.name,
                  url: emoji.skins[0].src,
                },
                children: [],
              } as Element);
            } else {
              pending.push({
                type: "text",
                value: matches[index],
              });
            }
          }

          return pending;
        },
        [] as Array<Element | Text>
      );
      parent.children.splice(index, 1, ...els);
      // skip over all the new elements we just created
      return [SKIP, index + els.length];
    }
  );
  return compiler;
};